bitmap: Add bitmap_copy_with_{src|dst}_offset()

These helpers copy the source bitmap to destination bitmap with a
shift either on the src or dst bitmap.

Meanwhile, we never have bitmap tests but we should.

This patch also introduces the initial test cases for utils/bitmap.c
but it only tests the newly introduced functions.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20190603065056.25211-5-peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

---

Bitmap test used sizeof(unsigned long) instead of BITS_PER_LONG.

1 files changed, 9 insertions, 0 deletions

diff --git a/include/qemu/bitmap.h b/include/qemu/bitmap.h
index 5c313346b9..82a1d2f41f 100644
--- a/include/qemu/bitmap.h
+++ b/include/qemu/bitmap.h
@@ -41,6 +41,10 @@
  * bitmap_find_next_zero_area(buf, len, pos, n, mask)	Find bit free area
  * bitmap_to_le(dst, src, nbits)      Convert bitmap to little endian
  * bitmap_from_le(dst, src, nbits)    Convert bitmap from little endian
+ * bitmap_copy_with_src_offset(dst, src, offset, nbits)
+ *                                    *dst = *src (with an offset into src)
+ * bitmap_copy_with_dst_offset(dst, src, offset, nbits)
+ *                                    *dst = *src (with an offset into dst)
  */
 
 /*
@@ -271,4 +275,9 @@ void bitmap_to_le(unsigned long *dst, const unsigned long *src,
 void bitmap_from_le(unsigned long *dst, const unsigned long *src,
                     long nbits);
 
+void bitmap_copy_with_src_offset(unsigned long *dst, const unsigned long *src,
+                                 unsigned long offset, unsigned long nbits);
+void bitmap_copy_with_dst_offset(unsigned long *dst, const unsigned long *src,
+                                 unsigned long shift, unsigned long nbits);
+
 #endif /* BITMAP_H */